Benzimidazole anthelmintic compounds have been intensively investigated ever since the discovery of thiabendazole in U.S. Pat. No. 3,017,415. Benzimidazole-2-carbamates containing a trifluoromethyl group on the benzo portion of the molecule group are disclosed in U.S. Pat. No. 3,574,845. Benzimidazole carbamates with an alkoxy, alkylthio, alkylsulfinyl or alkylsulfonyl on the benzo portion are disclosed in U.S. Pat. No. 3,922,824.